Which of Paul's letters are called the prison epistles and why?
Ephesians, Philippians, Colossians, and Philemon are called the prison epistles because they were written while Paul was imprisoned in Rome shortly before he was martyred. These letters emphasize the Body of Christ, with no reference to the Old Testament or Jew/Gentile distinction.
Les explains that Ephesians, Philippians, Colossians, and Philemon are normally referred to as the prison epistles, because they were written while Paul was in prison in Rome, shortly before he was martyred. He notes that in these prison epistles there is no single mention of the Old Testament, no reference back to it, and not one reference to the Jew. Everything has flowed into the teaching of the Body of Christ, in which there is no distinction—no Jew, no Gentile so far as a division of their background—and all have become one as members of the Body of Christ. Les emphasizes that this is strictly church ground, uniquely directed to the position of the church age believer, and not found in the Old Testament, the four Gospels, Acts, or even Paul's letters of Romans and Corinthians with this emphasis. He also mentions that ninety-some times in just six chapters the prepositional phrase “in Him,” “in Christ,” “in Whom” depicts our position.